1. Field of the Invention
The present invention relates to rotating magnetic disk drives, and more particularly, to techniques for efficiently determining and storing wedge repeatable runout (RRO) compensation values.
2. Description of the Prior Art and Related Information
With reference to FIGS. 7A and 7B, wedge repeatable runout (RRO) in a disk drive results from imperfections, with respect to a perfect circle, in the location of servo information 80 along a track 82 on a disk surface in the disk drive. During track following, the RRO imperfections have a detrimental effect on efforts by a head-position servo control loop to cause a transducer head to follow a perfect circle. The RRO imperfections are relatively static over time and the effects of the RRO may be attenuated by measuring the RRO and storing resulting RRO compensation values for later use by the head-position servo loop to compensate for the RRO.
Accordingly, there exists a need for a technique for efficiently determining and storing the RRO compensation values for significantly reducing the effects of RRO in a disk drive.